JP6388185B1 - Paint composition - Google Patents

Abstract

A coating composition capable of forming a coating film having excellent antifogging properties is provided.
A coating composition includes a first monomer having a repeating unit of an ethylene oxide group and a bifunctional or higher (meth) acryloyl group in one molecule, and a trifunctional or higher functional (meth) acryloyl group in a molecule. And a second monomer having one or more functional hydroxyl groups. Moreover, the number of the repeating unit of the ethylene oxide group in a 1st monomer is 18-40. And when the sum total of content of a 1st monomer and a 2nd monomer is 100 mass%, content of a 1st monomer is 40 mass%-95 mass%, and content of a 2nd monomer is 5 mass%. -60 mass%.
[Selection figure] None

Description

  The present invention relates to a coating composition. Specifically, the present invention relates to a coating composition capable of forming a coating film having antifogging properties.

  For example, in a mirror on a wash basin, when the surface temperature of the mirror becomes low in winter, the surface of the mirror may be condensed by water vapor in the air, and the mirror may become cloudy. In order to eliminate such fogging, various methods have been proposed.

  For example, Patent Document 1 describes that a hard coat or a cured coating film excellent in electrostatic property and antifogging property is formed by applying and curing a composition on the surface of a synthetic resin molded article. .

  It is described that the composition of patent document 1 contains the polyfunctional monomer (A) which has 3 or more of (meth) acryloyl groups, and the monofunctional or bifunctional monomer (B). Examples of the monomer (B) include polyethylene glycol mono (meth) acrylate, polyoxyethylene glycol mono (meth) acrylate, polyethylene glycol (meth) acrylate, and polypropylene glycol di (meth) acrylate.

  Moreover, the composition of the Example in patent document 1 contains 25 mass parts PE-4A and 30 mass parts PE-3A as a monomer (A), and 15 mass parts predetermined polyethylene as a monomer (B). It is described that glycol diacrylate is contained. PE-4A is pentaerythritol tetraacrylate, and PE-3A is pentaerythritol triacrylate.

Japanese Patent Laid-Open No. 5-214044

  According to Patent Document 1, the cured coating film obtained from the above composition is said to be excellent in all of scratch resistance, abrasion resistance, electrostatic property and antifogging property. However, since a coating film with higher antifogging property is demanded in the market these days, even the composition as described above cannot be said to have sufficient antifogging property, and further has excellent antifogging property. There is a need for coating compositions that can form films.

  The present invention has been made in view of such problems of the prior art. And the objective of this invention is providing the coating composition which can form the coating film excellent in anti-fogging property.

  In order to solve the above-described problems, a coating composition according to an embodiment of the present invention includes a first monomer having a repeating unit of an ethylene oxide group and a bifunctional or higher (meth) acryloyl group in one molecule, and one molecule. And a second monomer having a tri- or higher functional (meth) acryloyl group and a mono- or higher functional hydroxyl group. Moreover, the number of the repeating unit of the ethylene oxide group in a 1st monomer is 18-40. And when the sum total of content of a 1st monomer and a 2nd monomer is 100 mass%, content of a 1st monomer is 40 mass%-95 mass%, and content of a 2nd monomer is 5 mass%. -60 mass%.

  ADVANTAGE OF THE INVENTION According to this invention, the coating composition which can form the coating film excellent in anti-fogging property can be provided.

[Coating composition]
In Example 3 of Patent Document 1 described above, 25 parts by weight of PE-4A, 30 parts by weight of PE-3A, 25 parts by weight of NVP, 15 parts by weight of 45EO-DA, 20 parts by weight of EC and HCHPK A composition consisting of 5 parts by weight is described. Here, PE-4A is pentaerythritol tetraacrylate, PE-3A is pentaerythritol triacrylate, and NVP is N-vinyl-2-pyrrolidone. 45EO-DA uses polyethylene glycol diacrylate having 45 repeating units of ethylene oxide groups. EC is ethyl cellosolve and is used as a non-polymerizable solvent, and HCHPK is 1-hydroxycyclohexyl phenyl ketone and is used as a photopolymerization initiator.

  According to Patent Document 1, the cured coating film obtained from the above composition is said to be excellent in all of scratch resistance, abrasion resistance, electrostatic property and antifogging property.

  However, since a coating film with higher antifogging property is demanded in the market these days, even the composition as described above cannot be said to have sufficient antifogging property, and further has excellent antifogging property. There is a need for coating compositions that can form films.

  Here, as one means for improving the antifogging property of the coating film, it is conceivable to increase the number of repeating units of ethylene oxide groups which are hydrophilic groups. However, as described in Patent Document 1, when the number of ethylene oxide group repeating units is increased too much, not only the antifogging property of the coating film is decreased, but also electrostatic properties, scratch resistance and There is also a possibility that the wear resistance is also lowered.

  Moreover, in order to improve the antifogging property of a coating film, it is possible to increase content of polyethyleneglycol diacrylate like 45EO-DA. Here, in patent document 1, as content in the composition of a monomer (B), setting to the range of 5-30 weight part with respect to 100 weight part of compositions was excellent in the cured coating film. It is described that it is preferable from the viewpoint of imparting antifogging properties.

  However, even if the content of polyethylene glycol diacrylate such as 45EO-DA is increased to about 30 parts by mass, sufficient antifogging property may not be obtained. Moreover, when content of polyethyleneglycol diacrylate like 45EO-DA exceeds 30 mass parts, there exists a possibility that the hardness and water resistance of a coating film may fall. In Example 3 of Patent Document 1, PE-4A and PE-3A are considered to correspond to the monomer (A). In Example 3 of Patent Document 1, 45EO-DA is considered to correspond to the monomer (B). Therefore, in Example 3 described above, it is considered that the content of the monomer (B) is about 21% by mass when the total content of the monomer (A) and the monomer (B) is 100% by mass. Further, when the content of the monomer (B) in Example 3 is simply 30 parts by mass, the monomer (B) when the total content of the monomer (A) and the monomer (B) is 100% by mass. The content of is considered to be about 35% by mass.

  Therefore, the coating composition according to this embodiment includes a first monomer having a repeating unit of an ethylene oxide group and a bifunctional or higher (meth) acryloyl group in one molecule. Moreover, the coating composition which concerns on this embodiment contains the 2nd monomer which has a (meth) acryloyl group more than trifunctional and one or more hydroxyl groups in 1 molecule. Moreover, the number of the repeating unit of the ethylene oxide group in a 1st monomer is 18-40. And when the sum total of content of a 1st monomer and a 2nd monomer is 100 mass%, content of a 1st monomer is 40 mass%-95 mass%, and content of a 2nd monomer is 5 mass%. -60 mass%.

  The coating composition as described above contains a first monomer that mainly imparts antifogging properties to the coating film and a second monomer that primarily imparts hardness and water resistance to the coating film. The number of repeating units of the ethylene oxide group in the first monomer is within a predetermined range, and the contents of the first monomer and the second monomer are within a predetermined range. Therefore, the coating composition which concerns on this embodiment can form the coating film excellent in antifogging property, hardness, and water resistance by apply | coating to a base material and making it harden | cure. Hereinafter, each component will be described in detail.

(First monomer)
The coating composition which concerns on this embodiment has a 1st monomer which has a repeating unit of an ethylene oxide group and bifunctional or more (meth) acryloyl group in 1 molecule. That is, the first monomer has a repeating unit of an ethylene oxide group that contributes to antifogging properties, and a bifunctional or higher functional (meth) acryloyl group that contributes to the hardness and water resistance of the coating film by a polymerization reaction. .

  The first monomer can impart antifogging properties to the coating film by having a repeating unit of a hydrophilic ethylene oxide group. In addition, since the first monomer of this embodiment has a repeating unit of an ethylene oxide group in one molecule, compared with the case where an antifoggant is added to impart antifogging properties to the film, It is possible to reduce the influence of bleedout and functional deterioration due to aging.

The ethylene oxide group is represented by a structural unit of — (CH ₂ CH ₂ O) —. The first monomer has repeating units of ethylene oxide groups _(CH 2 _CH 2 O) in the molecule. Specifically, the number of ethylene oxide group repeating units in the first monomer is 18 to 40. By setting the number of repeating units of the ethylene oxide group to 18 or more, the chemical structure having hydrophilicity in the coating film increases, so that water vapor that causes condensation can be absorbed. Therefore, irregular reflection due to condensation can be suppressed, so that the antifogging property of the coating film can be improved. Moreover, the hardness and water resistance of a coating film can be improved by making the number of repeating units into 40 or less. From the viewpoint of antifogging property, the number of repeating units of the ethylene oxide group is preferably 20 or more, more preferably 22 or more, and further preferably 23 or more. From the viewpoints of hardness and water resistance, the number of ethylene oxide group repeating units is preferably 38 or less, more preferably 36 or less, and even more preferably 35 or less. In addition, the repeating unit of an ethylene oxide group may be repeated continuously within one molecule, or may be repeated discontinuously. Moreover, a 1st monomer may be used individually by 1 type, and may be used in combination of multiple types. In this specification, the number of repeating units of the ethylene oxide group is calculated by subtracting the molecular weight of the chemical structure other than the ethylene oxide group from the number average molecular weight _{Mn of} the first monomer, and dividing the value by the molecular weight of the ethylene oxide group. It is an integer.

In the first monomer, since the weight average molecular weight M _w tends to be _{equal to} or higher than the number average molecular weight M _n , the ratio of the weight average molecular weight M _w to the number average molecular weight M _n (M _w / M _n ) is generally Is 1 or more. Further, the value of M _w / M _n in the first monomer is preferably 1.4 or less, and more preferably 1.1 or less. In the present specification, the weight average molecular weight _Mw and the number average molecular weight _Mn can be calculated using gel permeation chromatography (GPC) and polyethylene glycol as a standard sample. Further, when the molecular weight distribution of the first monomer has a plurality of peaks, the weight average molecular weight _Mw and the number average molecular weight _Mn at each peak can be calculated.

The first monomer has a bifunctional or higher (meth) acryloyl group in one molecule. The (meth) acryloyl group is represented by —OCOCH═CH ₂ or —OCOC (CH ₃ ) ═CH ₂ and can form a polymer by a polymerization reaction. When the (meth) acryloyl group in one molecule is bifunctional or more, the crosslink density of the polymer forming the coating film can be improved as compared with the case of monofunctionality. Therefore, the water resistance of the coating film can be improved.

  The (meth) acryloyl group possessed by the first monomer includes a case of being bifunctional, trifunctional and tetrafunctional or more polyfunctional. However, from the viewpoint of antifogging properties, the (meth) acryloyl group of the first monomer is preferably at least one of bifunctional and trifunctional, and more preferably bifunctional. That is, the first monomer is more preferably di (meth) acrylate. In addition, although the (meth) acryloyl group in a 1st monomer includes a methacryloyl group and an acryloyl group, it is preferable that it is an acryloyl group from a viewpoint of a cure rate.

  The first monomer is preferably a monomer having a (meth) acryloyl group at both ends of the main chain containing a repeating unit of an ethylene oxide group. In addition, it is preferable that the ethylene oxide group having 18 to 40 repeating units is included in the main chain of the first monomer. By using such a first monomer in the coating composition, a coating film excellent in water resistance can be formed. The first monomer is represented by a polyethylene glycol di (meth) acrylate represented by the following chemical formula (1), an ethylene oxide-modified bisphenol A di (meth) acrylate represented by the following chemical formula (2), and the following chemical formula (3). Ethylene oxide-modified bisphenol F di (meth) acrylate, ethylene oxide-modified hexanediol di (meth) acrylate represented by the following chemical formula (4), and ethylene oxide-modified neopentyl glycol di (meta) represented by the following chemical formula (5) ) At least one monomer selected from the group consisting of acrylates can be used.

In the chemical formulas (1) to (5), R ₁ and R ₂ are each H or CH ₃ , l is an integer of 18 to 40, and m + n is an integer of 18 to 40.

  In addition, the monomer of the said Chemical formula (1)-(5) may be used individually by 1 type, and may be used in combination of 2 or more type. Moreover, it is preferable that a 1st monomer contains the polyethyleneglycol di (meth) acrylate represented by the said Chemical formula (1) from a viewpoint of anti-fogging property.

  Moreover, in order to improve the rigidity of a coating film, it is preferable that a 1st monomer contains the (meth) acrylate which has a bisphenol skeleton as shown to the said Chemical formula (2) and Chemical formula (3). From the viewpoint of antifogging properties and rigidity, the first monomer preferably contains polyethylene glycol di (meth) acrylate represented by the above chemical formula (1) and (meth) acrylate having a bisphenol skeleton. Specifically, the first monomer includes polyethylene glycol di (meth) acrylate represented by the above chemical formula (1), ethylene oxide-modified bisphenol A di (meth) acrylate represented by the above chemical formula (2), and the above chemical formula. It is also preferable to include at least one of ethylene oxide-modified bisphenol F di (meth) acrylate represented by (3). Moreover, it is also preferable that a 1st monomer contains the polyethyleneglycol di (meth) acrylate represented by the said Chemical formula (1), and the ethylene oxide modified bisphenol A di (meth) acrylate represented by the said Chemical formula (2). .

Specific examples of the first monomer include NK-Ester A-1000 (polyethylene glycol # 1000 diacrylate: Chemical Formula (1), R ₁ = H, R ₂ = H, and l = 23 from Shin-Nakamura Chemical Co., Ltd. NK-ester A-BPE-20 (EO (ethylene oxide) modified bisphenol A diacrylate) of Shin-Nakamura Chemical Co., Ltd .: In the above chemical formula (2), R ₁ = H, R ₂ = H and m + n = 20)) and the like can be used.

  The weight average molecular weight of the first monomer is preferably 800 g / mol to 3000 g / mol, and more preferably 850 g / mol to 2300 g / mol. By setting the weight average molecular weight of the first monomer in such a range, the coating characteristics of the coating composition can be improved.

  The content of the first monomer with respect to the entire solid content of the coating composition is preferably 35% by mass to 95% by mass, and more preferably 40% by mass to 85% by mass. By making content of a 1st monomer into said range, the coating composition which can improve the antifogging property of a coating film, water resistance, and hardness can be provided.

(Second monomer)
The second monomer has a (meth) acryloyl group having three or more functions and a hydroxyl group having one or more functions in one molecule. That is, the second monomer has a tri- or higher functional (meth) acryloyl group that contributes to the hardness and water resistance of the coating film by a polymerization reaction. Further, the second monomer has a monofunctional or higher functional hydroxyl group that contributes to the antifogging property of the coating film and suppresses reaction inhibition as a hydrogen donor and contributes to the improvement of the hardness of the coating film.

  The second monomer has a (meth) acryloyl group having three or more functions in one molecule. Therefore, since the polymer formed by the polymerization reaction forms a three-dimensional network structure, it is possible to improve the hardness and water resistance of the coating film as compared with the case of having a bifunctional or lower (meth) acryloyl group. it can. In addition, although the (meth) acryloyl group in a 2nd monomer includes a methacryloyl group and an acryloyl group, it is preferable that it is an acryloyl group from a viewpoint of a cure rate.

  The (meth) acryloyl group in the second monomer may be trifunctional or polyfunctional with 4 or more functions. However, from the viewpoint of suppressing curing shrinkage, the second monomer preferably has a trifunctional (meth) acryloyl group in one molecule.

  The hydroxyl group in the second monomer is not particularly limited as long as it has one or more functional hydroxyl groups. However, the hydroxyl group in the second monomer is preferably monofunctional.

  Specifically, it is more preferable that the second monomer has a trifunctional (meth) acryloyl group and a monofunctional hydroxyl group in one molecule. By using such a second monomer, a coating composition capable of forming a coating film excellent in antifogging properties, hardness and water resistance can be obtained.

  Examples of the second monomer include pentaerythritol tri (meth) acrylate, dipentaerythritol tri (meth) acrylate, dipentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, and ditrimethylolpropane tri (meth). An acrylate etc. are mentioned. These monomers may be used individually by 1 type, and may be used in combination of 2 or more type. Among these, it is preferable to use pentaerythritol tri (meth) acrylate from the viewpoint of coating properties. As the second monomer, New Frontier (registered trademark) PET-3 (pentaerythritol triacrylate) manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd. can be used.

  The weight average molecular weight of the second monomer is not particularly limited, but is preferably 230 g / mol to 800 g / mol, more preferably 260 g / mol to 600 g / mol, and 200 g / mol to 400 g / mol. More preferably. By setting the weight average molecular weight of the second monomer in such a range, the coating characteristics of the coating composition can be improved.

  The content of the second monomer with respect to the entire solid content of the coating composition is preferably 4% by mass to 60% by mass, and more preferably 10% by mass to 55% by mass. By making content of a 2nd monomer into said range, the coating composition which can improve the antifogging property of a coating film, water resistance, and hardness can be provided.

  In this embodiment, when the total content of the first monomer and the second monomer is 100% by mass, the content of the first monomer is 40% by mass to 95% by mass, and the content of the second monomer is It is 5 mass%-60 mass%. By making content of a 1st monomer and a 2nd monomer into the above ranges, the coating composition which can improve the antifogging property of a coating film, water resistance, and hardness can be provided. When the total content of the first monomer and the second monomer is 100% by mass, the content of the first monomer is 45% by mass to 85% by mass, and the content of the second monomer is 15% by mass. More preferably, it is -55 mass%. Further, when the total content of the first monomer and the second monomer is 100% by mass, the content of the first monomer is 50% by mass to 80% by mass, and the content of the second monomer is 20% by mass. More preferably, it is -50 mass%.

  The coating composition according to the present embodiment may further include a third monomer other than the first monomer and the second monomer in addition to the first monomer and the second monomer, as long as the effects of the present embodiment are not hindered. . Examples of the third monomer include a styrene monomer, an olefin monomer, a vinyl monomer, and an acrylic monomer. Examples of the styrene monomer include styrene. Examples of the olefin monomer include ethylene and propylene. Examples of the vinyl monomer include vinyl chloride and vinylidene chloride. As an acryl-type monomer, (meth) acrylate etc. are mentioned, for example. Note that (meth) acrylate includes acrylate and methacrylate. One of these monomer components may be used alone, or two or more thereof may be mixed and used. In the coating composition, the content of the third monomer is not particularly limited, but is preferably 0.001% by mass to 25% by mass, and 0.005% by mass to 15% by mass with respect to the entire coating composition. More preferably.

  In addition, it is preferable that a 3rd monomer contains the (meth) acrylate which has at least any one of a fluorine and polysiloxane in 1 molecule. These (meth) acrylates tend to localize on the surface after application of the coating composition. Moreover, since these (meth) acrylates can reduce the surface tension of the coating film itself, the surface of the coating film has water repellency and oil repellency. As above-mentioned, since the coating composition which concerns on this embodiment has the 1st monomer which has hydrophilic property, it has water absorption. On the other hand, in the coating composition containing (meth) acrylate having at least one of fluorine and polysiloxane in one molecule, the surface of the coating film has water repellency and oil repellency by curing. Therefore, even when the amount of water exceeds the amount of water absorbed by the first monomer or the like, water droplets on the surface of the coating film can be repelled by the water repellent effect of the monomer, so that the coating film is anti-fogged. Can be improved. Moreover, the coating film which hardened the coating composition containing the (meth) acrylate which has at least any one of a fluorine and polysiloxane also has oil repellency. Therefore, by adding (meth) acrylate having at least one of fluorine and polysiloxane to the coating composition, not only antifogging property but also antifouling property can be imparted to the coating film.

  The addition amount of (meth) acrylate having at least one of fluorine and polysiloxane in one molecule is not particularly limited as long as the effect of this embodiment is not hindered. In addition, (meth) acrylate having at least one of fluorine and polysiloxane in one molecule can exhibit the water repellency and oil repellency in a small amount. Therefore, the content of (meth) acrylate having at least one of fluorine and polysiloxane in one molecule is preferably 0.001% by mass to 5% by mass with respect to the entire coating composition. It is more preferable that it is 005 mass%-1 mass%.

  Examples of (meth) acrylate having fluorine in one molecule include trifluoromethyl (meth) acrylate, trifluoroethyl (meth) acrylate, perfluorodecylethyl (meth) acrylate, perfluorooctylethyl (meth) acrylate, perfluoro Examples include hexylethyl (meth) acrylate, perfluorobutylethyl (meth) acrylate, and perfluoropolyether (meth) acrylate.

  In addition, when using the (meth) acrylate which has polysiloxane as a 3rd monomer, the surface property of a coating film, such as slip property and a smooth feeling, can also be improved on the surface of a coating film. Therefore, it is preferable that the coating composition which concerns on this embodiment further contains the (meth) acrylate which has polysiloxane. For example, by imparting slip property to the surface of the coating film, the slip property of the coating film surface can be improved, so that an index such as pencil hardness can be improved. Moreover, the touch feeling of a coating-film surface can be improved by providing a smooth feeling to the surface of a coating-film.

  As (meth) acrylate having polysiloxane in one molecule, a structure having polysiloxane such as polydimethylsiloxane, polydiethylsiloxane, polydiphenylsiloxane, polymethylphenylsiloxane and the like as a main skeleton is modified with (meth) acrylate. And (meth) acrylate. In addition, as a specific example of (meth) acrylate having polysiloxane in one molecule, for example, Shin-Etsu Silicone (registered trademark) X-22-174ASX (methacrylate-modified silicone oil having polydimethylsiloxane by Shin-Etsu Chemical Co., Ltd.) )) Etc. can be used.

  It is preferable that the coating composition of this embodiment contains the polymerization initiator for accelerating the polymerization reaction of the 1st monomer provided with a carbon-carbon unsaturated bond, and a 2nd monomer. Although content of a polymerization initiator is not specifically limited, It is preferable to set it as 1 mass%-10 mass% with respect to the whole coating composition. As the polymerization initiator, at least one of a photopolymerization initiator and a thermal polymerization initiator can be used, but it is preferable to use a photopolymerization initiator. By using the photopolymerization initiator, the first monomer and the second monomer are instantaneously cured by irradiating the active energy ray, so that the manufacturing process can be shortened.

  A photopolymerization initiator is a compound that has a function of initiating a polymerization reaction of a first monomer and a second monomer, and is a substance that absorbs light of a specific wavelength from an active energy ray to be excited to generate radicals and ions. . As such a photopolymerization initiator, for example, at least one selected from the group consisting of benzoin ether series, ketal series, acetophenone series, benzophenone series, and thioxanthone series can be used. Specific examples of the photopolymerization initiator include Irgacure (registered trademark) 184 (1-hydroxycyclohexyl phenyl ketone (acetophenone series)) manufactured by BASF.

  The thermal polymerization initiator is a compound that has a function of initiating a polymerization reaction of the first monomer and the second monomer, and is a substance that generates active species such as radicals and ions by heating. The thermal polymerization initiator is at least one selected from the group consisting of azo compounds such as 2,2′-azobis (isobutyronitrile), peroxides such as benzoyl peroxide, benzenesulfonic acid esters and alkylsulfonium salts. Can be used.

  The coating composition according to the present embodiment may contain additives having various functions as long as the effects of the present embodiment are not hindered. As additives, surfactants, surface property modifiers, durability improvers, colorants, ultraviolet absorbers, light stabilizers, and the like can be used. These additives may be used individually by 1 type, and may be used in combination of 2 or more type.

  The surfactant can be added for the purpose of improving the leveling property and antifoaming property of the coating composition and making the surface of the coating film hydrophilic. The surfactant is not particularly limited, such as nonionic, cationic, and anionic, and can be selected according to the application. The surfactant may be chemically bonded to the first monomer or the second monomer to exhibit the above-described effect, and is not chemically bonded to the first monomer or the second monomer, but is interposed in these polymers to achieve the above-described effect. May be expressed.

  The surface property modifier can be added to the coating composition for the purpose of improving surface properties such as touch. As the surface property modifier, for example, a silicone monomer, a fluorine monomer or the like can be added. The surface property modifier can be chemically bonded to, for example, the first monomer or the second monomer to exhibit the above-described effect on the coating film.

  The durability improver can be added to the coating composition in order to improve the durability against chemicals, heat and sliding. As the durability improver, for example, a material having a rigid chemical structure such as a benzene ring or a bisphenol structure or a flexible chemical structure such as an alkane can be used.

  Next, the manufacturing method of the coating composition of this embodiment is demonstrated. The coating composition can be adjusted by mixing the first monomer and the second monomer and additives to be added as necessary. The mixing conditions are not particularly limited, and the mixing can be performed in the atmosphere at room temperature. Further, the mixing order of the first monomer, the second monomer and the additive is not particularly limited.

  When mixing the first monomer, the second monomer, and the like, it is preferable to add a dispersion solvent to the coating composition to adjust the viscosity so that it can be easily applied. As the dispersion solvent for adjusting the viscosity, at least one of water and an organic solvent can be used. The organic solvent is not particularly limited, but it is preferable to appropriately select an organic solvent that volatilizes easily at the time of coating film formation and does not cause curing inhibition at the time of coating film formation. Examples of the organic solvent include aromatic hydrocarbons (such as toluene and xylene), alcohols (such as methanol, ethanol, and isopropyl alcohol), and ketones (such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone). Furthermore, aliphatic hydrocarbons (such as hexane and heptane), ethers (such as tetrahydrofuran), amide solvents (such as N, N-dimethylformamide (DMF) and dimethylacetamide (DMAc)), methyl acetate, and butyl acetate are exemplified. It is done. These organic solvents may be used individually by 1 type, and may be used in combination of 2 or more type. Although the addition amount of a dispersion | distribution solvent is not specifically limited, For example, it is 0.1 mass part-500 mass parts with respect to 100 mass parts coating composition.

  As mentioned above, the coating composition which concerns on this embodiment contains the 1st monomer which has the repeating unit of an ethylene oxide group and the bifunctional or more (meth) acryloyl group in 1 molecule. Moreover, the coating composition which concerns on this embodiment contains the 2nd monomer which has a (meth) acryloyl group more than trifunctional and one or more hydroxyl groups in 1 molecule. Moreover, the number of the repeating unit of the ethylene oxide group in a 1st monomer is 18-40. And when the sum total of content of a 1st monomer and a 2nd monomer is 100 mass%, content of a 1st monomer is 40 mass%-95 mass%, and content of a 2nd monomer is 5 mass%. -60 mass%.

  As described above, the coating composition according to the present embodiment includes a first monomer that mainly imparts antifogging properties to the coating film and a second monomer that primarily imparts hardness and water resistance to the coating film. . In this embodiment, the number of repeating units of the ethylene oxide group in the first monomer and the contents of the first monomer and the second monomer are within a predetermined range. Therefore, according to the coating composition which concerns on this embodiment, the coating film excellent not only in the antifogging property of the coating film formed with the coating composition but also in hardness and water resistance can be formed. Therefore, according to the coating composition concerning this embodiment, the coating film excellent in antifogging property, hardness, and water resistance can be formed.

  In addition, since the coating film obtained from the above coating composition has high hydrophilicity, oil stains can be floated using a large amount of water, and oil stains can be easily removed. Therefore, according to the coating composition which concerns on this embodiment, it becomes possible to improve the antifouling property with respect to an oil component.

  Since the coating composition according to the present embodiment has anti-fogging properties, it can be applied to members such as housing members, vehicle members, and security members. As a member used for these, a mirror, a window glass, a lens, a display etc. are mentioned, for example. Moreover, since the coating film formed using the coating composition which concerns on this embodiment has hydrophilicity, it has antifouling property with respect to an oil component. Therefore, it can be applied to a residential member such as a kitchen member. It can also be applied to sirocco fans and propeller fans installed in the kitchen range hood.

[Hydrophilic member]
Next, the hydrophilic member according to the present embodiment will be described. The hydrophilic member which concerns on this embodiment is provided with a base material and the hydrophilic film which is provided on a base material and is formed from the said coating composition. That is, the hydrophilic member according to the present embodiment forms a hydrophilic film (coating film) having hydrophilicity by applying the coating composition to a base material and curing the coating composition.

  The substrate is not particularly limited, and at least one of an inorganic substrate made of an inorganic material and an organic substrate made of an organic material can be used. Examples of the inorganic base material include ceramics such as aluminum, iron, stainless steel, galvanized steel sheet, glass, enamel, earthenware, slate, and alumina. Examples of the organic base material include polycarbonate, acrylic resin, ABS resin (acrylonitrile-butadiene-styrene resin), vinyl chloride resin, epoxy resin, polyester resin, fiber reinforced plastic, and other plastic materials and sheets. Examples of the fiber reinforced plastic include carbon fiber reinforced plastic, glass fiber reinforced plastic, SMC (sheet molding compound), and the like.

  In addition, those obtained by coating an organic coating on these inorganic or organic substrates may be used as the substrate. Examples of the organic coating include acrylic, polyester, urethane, epoxy, melamine, silicone, and fluorine coatings. In order to improve the adhesion between these films and the substrate, surface treatment such as solvent degreasing, alkali degreasing, and polishing may be performed on the substrate, and acrylic, epoxy, and silicone primers may be used. You may make it apply | coat to a base material as a base layer.

  The hydrophilic film is formed by curing the above-described coating composition. The hydrophilic film is formed by a polymer of the first monomer and the second monomer.

  In the hydrophilic member, the thickness of the hydrophilic film is not particularly limited, but is preferably 1 μm to 100 μm, for example, and more preferably 10 μm to 80 μm. When the thickness of the hydrophilic film is within this range, the hardness and water resistance can be increased. Further, when the thickness of the hydrophilic film is 100 μm or less, it is possible to firmly bond to the substrate and suppress peeling.

  In the hydrophilic member, the contact angle of water on the surface of the hydrophilic film is preferably 20 ° or less, and more preferably 10 ° or less. When the contact angle of water on the surface of the hydrophilic film is 20 ° or less, the hydrophilic film has high hydrophilicity. Therefore, it becomes possible to improve anti-fogging properties or to easily remove oil adhering to the surface of the hydrophilic film. The contact angle of water can be measured by a sessile drop method.

  Next, the manufacturing method of the hydrophilic member of this embodiment is demonstrated. First, the surface of the substrate is washed to remove the surface dirt. The cleaning method is not particularly limited, and a known method can be used.

  Next, the above-mentioned coating composition is applied to the surface of the cleaned substrate. At this time, the method for applying the coating composition is not particularly limited. As a method of applying the coating composition to the main surface of the substrate, a coating method or a printing method can be used. In the coating method, the coating composition can be applied using an air spray, a brush, a bar coater, a Mayer bar, an air knife, or the like. Also, the coating composition can be applied by spin coating. As the printing method, methods such as gravure printing, reverse gravure printing, offset printing, flexographic printing, and screen printing can be used.

  In addition, after apply | coating a coating composition to the surface of a base material, a drying process may be performed as needed and the dispersion | distribution solvent in a coating composition may be removed. The drying conditions are not particularly limited as long as the dispersion solvent is removed, and heat treatment may be performed as necessary.

  And when a photoinitiator is used as a polymerization initiator, after apply | coating a coating composition to the surface of a base material, an active energy ray is irradiated and a coating composition is hardened. As an active energy ray to be irradiated when the coating composition is cured, at least one of ultraviolet rays, electron beams, X-rays, infrared rays, and visible rays can be used. Of these active energy rays, ultraviolet rays or electron beams are preferably used from the viewpoint of curability and prevention of resin deterioration.

When the coating composition is cured by ultraviolet irradiation, various ultraviolet irradiation apparatuses can be used. As the ultraviolet irradiation device, a xenon lamp, a high-pressure mercury lamp, a metal halide lamp, or the like can be used. And the irradiation amount of an ultraviolet-ray is 10-10000 mJ / cm < ² > normally. However, from the viewpoint of enhancing the curability of the composition, the irradiation amount of ultraviolet rays is preferably 100 mJ / cm ² or more. Moreover, it is preferable to irradiate ultraviolet rays in a nitrogen atmosphere so that curing inhibition is not caused by oxygen in the air.

  When a thermal polymerization initiator is used as the polymerization initiator, after the coating composition is applied to the surface of the substrate, the coating composition is heated to cure the coating composition. In addition, heating conditions are not specifically limited, It can be set as the temperature which the thermal-polymerization initiator to use decompose | disassembles and generate | occur | produces active species.

  As described above, the hydrophilic member of the present embodiment can be produced by applying a coating composition to a substrate and then curing it. Therefore, a hydrophilic member having high hydrophilicity can be obtained by a simple method.

  Thus, the hydrophilic member which concerns on this embodiment is provided with a base material and a hydrophilic film | membrane provided on a base material and formed from a coating composition. The hydrophilic film has high antifogging property, hardness and water resistance. In addition, since the hydrophilic film has high hydrophilicity, even when oil such as oil stains adheres to the hydrophilic film, water is infiltrated between the surface of the hydrophilic film and the oil by bringing water into contact with the hydrophilic member. Can be made. And since water infiltrates and an oil component floats from a hydrophilic film, it becomes possible to remove an oil component easily.

  Examples of the hydrophilic member include members such as housing members, vehicle members, and security members. Specifically, a mirror, a window glass, a lens, a display, etc. are illustrated. Moreover, the hydrophilic member which concerns on this embodiment can also be used for the sheet | seat for greenhouses for which anti-fog property is required, the packaging for foodstuffs other than the above members.

  In addition, the hydrophilic member according to the present embodiment is not limited to use for the purpose of anti-fogging property, and can be suitably used for a site where hydrophilicity needs to be imparted, such as removal of oil. When used for oil removal, examples of the hydrophilic member include kitchen members such as a range hood, a kitchen storage door, a kitchen counter, a sink, a hob, a kitchen board, a flooring around the kitchen, and a refrigerator. Thus, oil stains such as lipid peroxide are likely to adhere to the surface of the kitchen member or the like. However, by providing the hydrophilic film of the present embodiment, it is possible to easily remove the initial oil stain just after adhering and the viscous oil using water. The oil stain is typically edible oil used in the kitchen, but is not limited thereto, and oils and fats caused by hand dirt, fingerprints, sebum, sweat and the like can also be removed.

  Hereinafter, the present embodiment will be described in more detail with reference to examples and comparative examples, but the present embodiment is not limited to these examples.

  The coating compositions of Examples and Comparative Examples were prepared as follows. Specifically, the monomer A, monomer B, monomer C, photopolymerization initiator, and dispersion solvent shown below were mixed in the amounts shown in Table 1, Table 4, and Table 6. At this time, as a stirrer, a rotating / revolving mixer Awatori Nertaro (registered trademark) (manufactured by Sinky Co., Ltd.) was used, and these materials were mixed thoroughly by stirring at a predetermined rotational speed. A composition was obtained. In addition, the content rate of the monomer A in Table 1, Table 4, and Table 6 means the ratio of the mass of the content of the monomer A with respect to the total content of the monomer A and the monomer B.

(Monomer A)
Monomer A1: Polyethylene glycol diacrylate having 9 repeating units of ethylene oxide groups (see the following chemical formula (6))

  Monomer A2: polyethylene glycol diacrylate having 14 ethylene oxide group repeating units (see the following chemical formula (7))

  Monomer A3: Polyethylene glycol diacrylate having 23 repeating units of ethylene oxide group (see the following chemical formula (8))

  Monomer A4: polyethylene glycol diacrylate having 35 repeating units of ethylene oxide group (see the following chemical formula (9))

  Monomer A5: Polyethylene glycol diacrylate having 46 repeating units of ethylene oxide groups (see the following chemical formula (10))

  Monomer A6: EO (ethylene oxide) modified bisphenol A diacrylate having 20 repeating units of ethylene oxide group (see the following chemical formula (11))

(Monomer B)
Monomer B1: Pentaerythritol triacrylate (see the following chemical formula (12))

(Monomer C)
Monomer C1: EO (ethylene oxide) -modified bisphenol A diacrylate having 4 ethylene oxide group repeating units (see the following chemical formula (13))

  Monomer C2: Methacrylate (methacryl-modified silicone oil) having polydimethylsiloxane (see chemical formula (14) below)

(Photopolymerization initiator)
1-hydroxycyclohexyl phenyl ketone

(Dispersion solvent)
2-butanone (methyl ethyl ketone (MEK))

Next, a 100 mm × 100 mm mirror having an outermost surface formed of an acrylic resin was prepared as a substrate, and the surface of the substrate was washed. And after apply | coating the coating composition of each example to the surface of a base material with the bar coater, it was made to dry at 80 degreeC for 5 minute (s), and the dispersion solvent was removed. Thereafter, the applied coating composition was irradiated with ultraviolet rays at 600 mJ / m ² in a nitrogen atmosphere to cure the coating composition. Thereby, the test sample of each example which formed the coating film (hydrophilic film) on the surface of the base material was adjusted. In addition, ultraviolet irradiation was performed using Ushio Electric Co., Ltd. product, Spot UV irradiation apparatus Spot Cure (trademark) SP-9. Moreover, the thickness of the coating film in the test sample of each example was about 50 μm.

[Evaluation]
About each test sample, pencil hardness, anti-fogging property, and water resistance were evaluated as follows. The evaluation results of each test sample are shown in Tables 2, 5 and 7. Table 3 shows the results of Table 2 arranged in the relationship of “content ratio of monomer A” and “number of repeating units of ethylene oxide group in monomer A”. In each table, “content ratio of monomer A” means the ratio of the mass of the content of monomer A to the total content of monomer A and monomer B.

(Pencil hardness)
Pencil hardness is Japanese Industrial Standard JIS K5600-5-4: 1999 (ISO / DIS 15184: 1996). ) And measured. And pencil hardness was evaluated based on the following references | standards.
◎: Pencil hardness F or higher ○: Pencil hardness HB and B
X: Pencil hardness 2B or less

(Anti-fogging property)
The antifogging property was measured in a 25 ° C. and 75% RH atmosphere after the temperature of the test sample was set to 10 ° C. until the substrate began to become visually cloudy. And antifogging property was evaluated based on the following criteria.
○: Cloudiness of the test sample was not visually observed for 60 seconds or more. ×: Cloudiness of the test sample was visually observed in less than 60 seconds.

(water resistant)
For water resistance, a test sample immersed in 25 ° C. ion-exchanged water was taken out every day and the appearance was visually observed. And water resistance was evaluated based on the following criteria.
○: No change in appearance for 7 days or more ×: Peeling of the coating film was observed within 6 days

  As shown in Tables 1 to 3, when the number of repeating units of the ethylene oxide group in the monomer A is 23 or 35 and the content of the monomer A is 50% by mass to 90% by mass, the pencil hardness In addition, both the anti-fogging property and the water resistance were evaluated as ◎ or ○. Furthermore, when the content of the monomer A was 80% by mass, the pencil hardness was judged as ◎.

  On the other hand, when the number of repeating units of the ethylene oxide group in the monomer A was 14 or less, the determination of antifogging property was x. Further, even when the number of repeating units of the ethylene oxide group in the monomer A was 23 or more, when the content of the monomer A was 33% by mass or less, the determination of antifogging property was x.

  Further, when the number of repeating units of the ethylene oxide group in the monomer A was 46, when the content of the monomer A was 50% by mass or more, the water resistance was judged as x. Furthermore, when the number of repeating units of the ethylene oxide group in the monomer A is 46, the pencil hardness is judged to be good when the monomer A content is 80% by mass, and the pencil hardness is 90% by mass when the monomer A content is 90% by mass. The judgment of became X.

  From Tables 4 and 5, it was found that when the coating film was formed using the coating composition as in Example 9 and Example 10, the pencil hardness, antifogging property and water resistance were improved. That is, it was found that even if a part of polyethylene glycol diacrylate was replaced with EO-modified bisphenol A diacrylate, a coating film excellent in antifogging property, hardness and water resistance could be formed under predetermined conditions. . Specifically, it was found that when the number of repeating units of the ethylene oxide group and the content of the monomer A are in a predetermined range, a coating film excellent in antifogging property, hardness, and water resistance can be formed.

  From Table 6 and Table 7, when a coating film was formed using the coating composition like Example 12, it turned out that pencil hardness becomes more favorable. That is, it was found that when methacryl-modified silicone oil was added as monomer C in addition to monomer A and monomer B, the pencil hardness was improved.

  As described above, when the number of repeating units of the ethylene oxide group in the monomer A is in a predetermined range and the content ratio of the monomer A and the monomer B is in a predetermined range, the coating excellent in antifogging property, hardness and water resistance. It has been found that a film can be formed.

  Although the present embodiment has been described above, the present embodiment is not limited to these, and various modifications can be made within the scope of the gist of the present embodiment.

Claims (3)

A first monomer having a (meth) acryloyl groups in the repeating units and 2 officers ability of ethylene oxide groups per molecule,
A second monomer having a (meth) acryloyl group having three or more functions and a hydroxyl group having one or more functions in one molecule;
Including
The number of repeating units of the ethylene oxide group in the first monomer is 18 to 40,
When the total content of the first monomer and the second monomer is 100% by mass, the content of the first monomer is 40% by mass to 95% by mass, and the content of the second monomer is 5%. Ri mass% to 60% by mass,
The content of the first monomer with respect to the entire solid content is 40% by mass to 85% by mass,
The content of the second monomer to the total solid content Ru 10 weight% to 55% by mass, the coating composition. 2. The coating composition according to claim 1, wherein the first monomer is a di (meth) acrylate monomer having each of the (meth) acryloyl groups at both ends of the main chain including the repeating unit of the ethylene oxide group.   The coating composition according to claim 1, further comprising (meth) acrylate having polysiloxane.